GB2631461A

GB2631461A - A roof assembly comprising a wall plate

Info

Publication number: GB2631461A
Application number: GB2310013.4A
Authority: GB
Inventors: Ross Shenton Edward
Original assignee: Sano Development Ltd
Current assignee: Sano Development Ltd
Priority date: 2023-06-30
Filing date: 2023-06-30
Publication date: 2025-01-08
Anticipated expiration: 2043-06-30
Also published as: GB202310013D0; GB2631461B

Abstract

There is disclosed a roof assembly (124) for a building (10a), a building comprising the roof assembly, and an associated method. The roof assembly (124) comprises: at least two elongate joists (126, 128, 136-144); and an insulated wall plate (28e) comprising a loadbearing structural part (56e), an insulation part (58e) carried by the load-bearing structural part, and a main axis (130) extending along a length direction of the wall plate. The elongate joists are connected to the wall plate at respective connection locations (132, 134) on the wall plate which are spaced apart along its main axis. The roof assembly is configured to be installed in the building as a unitary structure comprising the elongate joists and the insulated wall plate. The insulated wall plate is configured to be seated on a load-bearing structural wall (16a) of the building, to thereby connect the elongate joists to the wall.

Description

A ROOF ASSEMBLY COMPRISING A WALL PLATE

The present invention relates to a roof assembly for a building which comprises an elongate joist and a wall plate, a building comprising the roof assembly, and an associated method. A load-bearing structural wall for a building comprising a roof, a building comprising a load-bearing structural wall and a roof, a wall plate configured to form part of a load-bearing structural wall of such a building and associated methods are also disclosed.

in building construction, residential buildings such as houses commonly have a pitched roof comprising a plurality of roof trusses. The pitched roof can comprise two roof portions which slope downwardly in opposite directions from an apex (or ridge) of the roof towards respective edge regions, known as eaves. Another example comprises a single roof portion which extends from a high side at one edge of the building to a low side at an opposite edge.

In the former example, the roof trusses each typically comprise a pair of rafters which extend downwardly in opposite directions from an apex of the truss, and ties which extend laterally between and connect the rafters. in the latter example, the roof trusses are generally of a right-angled triangle shape, comprising a rafter which slopes downwardly from the high to the low side, and bracing beneath the rafter. In both cases, the trusses are supported by a wall structure of the building, suitably by an elongate component known as a wall plate. The wall plate is positioned on a top surface of the wall structure, extending along its length, and is usually of a timber material.

Many options exist for forming the wall structure. One option is a cavity wall structure comprising inner and outer wall skins separated by a cavity, which is usually filled with an insulation material. The inner wall skin can be of masonry such as blockwork, for example cement-based blocks such as breeze or cinder blocks. The outer wall skin provides a weatherproof finish, and can also be of masonry, for example clay bricks.

A timber wall plate around 1.5" (-3.8cm) deep is positioned on an upper surface of the inner wall skin, which is defined by an upper course of blocks. The wall plate is secured to the inner wall skin using a number of straps or tics, which pass over a top surface of the wall plate, and then extend downwardly along an interior surface of blocks forming the inner wall skin. Truss rafters are connected to the wall plate to secure the roof to the wall structure, typically using dedicated connector plates. The wall plate serves to distribute the load exerted by the roof structure down through the wall without creating pressure points where each rafter meets the wall, and also serves to prevent wind uplift.

The roof space is normally insulated, to resist thermal energy transfer through a ceiling structure of the building, which defines a lower boundary of the roof space. The insulation is positioned above an inner skin of the ceiling, and extends laterally into the roof eaves. The insulation should ideally pass over the wall plate on the inner wall skin to a position adjacent an inner surface of the roof, between the rafters of adjacent trusses. This serves to insulate a to void located below the inner roof surface adjacent the eaves, in the region of the inner and outer wall skins. Insertion of insulation into the void can however be difficult, as the opening into it from the main roof space is usually quite small. This can have the result that the void is inadequately insulated, because the insulation does not extend all the way into it over the wall plate and outer wall skin. This can lead to cold zones (or 'cold spots') forming along an upper part of the inner wall skin. Consequences of this can include heat loss, and damp patches appearing on the internal surface of the inner wall skin, caused by moisture in the building condensing on the cold wall surface.

The issues outlined above are not limited to double-skinned walls comprising a cavity, and can also occur in single skin walls. Single skin wall options include a poured concrete wall structure, and a wall structure formed from cement-based blocks, having an external insulation layer. In both cases, a wall plate is fitted to an upper surface of the wall structure, and roof truss rafters connected to the wall plate as described above. A void again exists, adjacent the eaves and below the inner roof surface. Similar difficulties occur when insulating the void.

Problems can also be encountered in buildings having alternative roof structures, including flat' roof structures (i.e. ones without a pitch, and which do not typically comprise an cave void as described above). In particular, cold zones can occur on inner wall skins if insulation is not correctly installed in a wall cavity, for example if the insulation does not extend to a full height of the wall skin.

According to a first aspect of the present building, the roof assembly comprising: nven on. there is provided a roof assembly for a at least two elongate joists; and an insulated wall plate comprising a load-bearing structural part, an insulation part carried by the load-bearing structural part, and a main axis extending along a length direction of the wall plate; in which the elongate joists are connected to the wall plate at respective connection locations on the wall plate which arc spaced apart along its main axis; in which the roof assembly is configured to be installed in the building as a unitary structure comprising the elongate joists and the insulated wall plate; and in which the insulated wall plate is configured to be seated on a load-bearing structural wall of the building, to thereby connect the elongate joists to the wall.

According to a second aspect of the present invention, there is provided a building construction system comprising: a load-bearing structural wall: and a roof assembly configured to be connected to the load-bearing structural wall, the roof assembly comprising: at least two elongate joists; and an insulated wall plate comprising a load-bearing structural part, an insulation part carried by the load-bearing structural part, and amain axis extending along a length direction of the wall plate; in which the elongate joists arc connected to the wall plate at respective connection locations on the wall plate which are spaced apart along its main axis, to form a unitary structure defining the roof assembly and comprising the elongate joists and the wall plate: and in which the insulated wall plate is configured to be seated on the load-bearing structural wall, to thereby connect the elongate joists to the wall.

According to a third aspect of the present invention, there is provided a building comprising a load-bearing structural wall, and a roof assembly connected to the load-bearing structural wall, in which the roof assembly is a unitary structure comprising: at least two elongate joists; and an insulated wall plate comprising a load-bearing structural part, an insulation part carried by the load-bearing structural part, and a main axis extending along a length direction of the wall plate, the elongate joists being connected to the wall plate at respective connection locations on the wall plate which arc spaced apart along its main axis; in which the insulated wall plate is seated on the load-bearing structural wall, to thereby connect the elongate joists to the wall; and in which the roof assembly is configured to be installed in the building as a unitary structure comprising the elongate joists and the insulated wall plate.

The invention may help to address problems which occur in conventional building construction, in which inadequately insulated roof space voids lead to heat loss and cold spots forming on an upper part of a structural wall. This is because the insulated wall plate can effectively provide an upper (or second) portion of the wall structure. Even if insulation is subsequently positioned in a sub-optimal fashion (e.g. in a void adjacent an cave of a pitched roof), the insulation part of the wall plate serves to resist thermal energy transfer through the wall structure, and so the formation of cold spots.

The invention may facilitate installation of a roof on a building, because the unitary nature of the roof assembly (comprising the joists and wall plate in a unitary structure) may allow installation to be achieved in a single construction step. This is in contrast for example to existing roof assemblies, which require that a wall plate be installed on a load-bearing structural wall prior to connection of any joists, and also that the joists be individually installed and connected to the plate.

Optional further features of the roof assembly, building construction system and building of the first, second and third aspects may be derived from the following text.

The insulated wall plate may be a first insulated wall plate, and the roof assembly may comprise a second insulated wall plate. The second insulated wall plate may comprise a load-bearing structural part, an insulation part carried by the load-bearing structural part, and a main axis extending along a length direction of the wall plate. The elongate joists may be connected to the second wall plate at respective connection locations on the second wall plate which are spaced apart along its main axis. The first insulated wall plate may be configured to be seated on a first load-bearing structural wall of the building. The second insulated wall plate may be configured to be seated on a second load-bearing structural wall of the building, to thereby connect the elongate joists to said second wall. The first and second insulated wall plates may be disposed substantially parallel to each other, in the unitary roof assembly structure. The first and second wall plates may be disposed spaced apart in the unitary roof assembly structure, optionally in length directions of the elongate joists.

The elongate joists may each comprise a first end, and a second end opposite the first end.

The elongate joists may each be connected to the wall plate at their first ends. Where the roof assembly comprises first and second insulated wall plates, the elongate joists may each be connected to the first wall plate at their first ends, and to the second wall plate at their second ends. The unitary roof assembly structure may comprise the elongate joists and both the first and second insulated wall plates.

The roof assembly may comprise more than two elongate joists. Each joist may be connected to the insulated wall plate at a respective connection location which is spaced apart along the main axis from the connection locations for other joists. Each joist may have a first end and a second end opposite the first end, and may be connected to the insulated wall plate (or first and second insulated wall plates, where present) in the same way as the elongate joists described above. The elongate joists may all form part of the unitary roof assembly structure.

The elongate joists may be arranged so that they are substantially parallel to one another, in the unitary roof assembly structure. The elongate joists may be disposed transverse to the insulated wall plate, optionally to both of the first and second insulated wall plates (where present), and may be disposed substantially perpendicular to said plate(s).

The unitary roof assembly structure may take the general form of a frame or frame-type assembly. The unitary roof assembly structure may be configured to form a ceiling in the building, and/or a floor of a roof space or void of the building. The elongate joists may be configured to define floor and/or ceiling joists in the building.

The elongate joists may comprise a recess shaped to receive the insulated wall plate, for example at their ends. A recess may be provided at each of the first and second ends of the joists, for respectively receiving the first and second wall plates. The elongate joists may each comprise a support surface configured to rest on an upper surface of the insulated wall plate, for supporting the joists on the wall plate. The support surfaces may be defined on or by parts of the joists which extend from a main part or portion of the joist.

The elongate joists may be connected to the insulated wall plate or plates via a mechanical fixing (e.g. one or more bolt, screw, nail and/or a dedicated fixing plate), and/or may be bonded to the wall plate(s), e.g. using an adhesive.

The elongate joists may comprise elongate upper and lower support members and at least one connection member extending between and connecting the upper and lower support members. The elongate joists may be composite joists in which the upper and lower support members are of a first material, and the connecting member is of a second material which is different to the first material. Material properties of the first and second materials may differ, e.g. the first material may be a timber or timber-based material, and the second material a metal or metal alloy material. The elongate joists may have a non-solid cross-section, which may be in a vertical plane/height direction. The connection member may be a web comprising web members which extend in directions transverse to a main longitudinal axis of the joist between the upper and lower support members to connect the support members. The web may have a generally undulating profile, considered in the direction of the main axis of the joist. Alternatively, the elongate joists may have a substantially solid cross-section, and may be of a single material (e.g. a timber or timber-based material).

The insulation part of the wall plate may be connected to the load-bearing structural part.

The insulation part of the wall plate may be configured to engage the structural part in an interference fit (which may retain the insulation part in connection with the structural part). For example, the insulation part may be slightly oversized relative to a cavity defined by the structural part and which is shaped to receive the insulation part, so that the insulation part is compressed during fitting to the structural part. The insulation part may comprise an elongate strip or strips of insulation material, which may be connected to the structural part.

The insulation part of the wall plate may be bonded to the structural part. Bonding may be achieved using an adhesive.

The insulation material may have inherent adhesive properties. A manufacturing process for the wall plate may involve applying insulation material to the structural part in a fluid or flowablc state (e.g. as a spray foam), the insulation material setting over time to a substantially solid state (in which it is no longer fluid or flowablc), in which it defines the insulation part. During setting, a volume of the insulation part may increase slightly to provide an interference fit, and/or the material may provide an adhesive bond to the structural part.

A thermal conductivity of a material forming the insulation part may be lower than a thermal conductivity of a material forming the load-bearing structural part. The insulation part may be of a material having a thermal conductivity of up to around 0.04W/m.K, and suitably in a range of about 0.022 to about 0.04W/m.K, in particular about 0.035 to about 0.04W/m.K. Suitable insulation materials can include polymers such as extruded polystyrene (XPS) and expanded polystyrene (EPS), which have thermal conductivities that are typically in the range of about 0.035 to about 0.04W/m.K. Plowable insulation materials such as foams as described above may be of a polymeric material such as polyureth'mc (PU), which can have a lower thermal conductivity, e.g. in the range of about 0.022 to about 0.028W/m.K.

The load-bearing structural part of the wall plate may be elongate. Said structural part may comprise at least one cavity (which may be the cavity mentioned above), which may be shaped to receive the insulation part, and which may take the form of a channel, groove, recess or the like.

The load bearing structural part may comprise atop plate member. The top plate member may define an upper edge surface of the wall plate. The top plate member may define the connection locations. The load bearing structural part may comprise a bottom plate member. The bottom plate member may define a bottom edge surface of the wall plate, which may be configured to rest on an upper edge surface of the load-bearing structural wall. Said plate members may each extend in a main length direction of the structural part. One or more connecting member may extend between and connect the top and bottom plate members.

The load-bearing structural part may be substantially hollow, and/or may comprise an internal or interior cavity which may define said channel. The load bearing structural part may take the general form of an elongate hollow box (optionally generally rectangular in shape in cross-section). The box may comprise said interior cavity, and the cavity may be open at one or both of first and second ends of said structural part. The load-bearing structural part may comprise a pair of connecting members, each of which may extend between and connect the top and bottom plate members. The connecting members may be arranged so that the cavity which is defined is bound by a lower surface of the top plate member, internal surfaces of the connecting members, and an upper surface of the bottom plate member. The connecting members may each take the form of a panel. There may be first and second panels, the first panel coupled to and extending between respective first side surfaces of the top and bottom plate members, and the second panel coupled to and extending between respective second side surfaces of the top and bottom plate members.

The load-bearing structural part may comprise a single connecting member, which may form a structural core of said part. The top and bottom plate members and the structural core may be provided as separate components which are coupled together, or as a single/unitary component. A width of the structural core (which may be considered in a direction perpendicular to the main length direction and suitably generally horizontally in use of the wall plate) may be less than a width of one or both of the top and bottom plate members. The structural core may be disposed generally along a centreline of said structural part, and may connect with the top and bottom plate members generally at a midpoint of the members, considered in a width direction. Said channel may be disposed on a side of the structural core, and may be bound by a lower surface of the top plate member, a side surface of the structural core, and an upper surface of the bottom plate member. Said channel may be open on one side, suitably on a side facing laterally and/or away from the structural core. A first such channel may be defined which is disposed on a first side of the structural core, and a second such channel may be defined which is disposed on a second side of the core. The load bearing structural part may be generally 1-shaped in cross-section.

A thermal conductivity of a material forming the load bearing structural part may be higher than a thermal conductivity of a material forming the insulating part. The load bearing structural part may be of a material having a thermal conductivity of up to around 0.17W/m.K, and suitably in a range of about 0.11 to about 0.17W/m.K. Suitable materials can include timber (softwoods and hardwoods), and timber based composite materials including wood fibreboard and chipboard, and laminates such as plywood. Other materials can include polymeric materials, and composite materials such as fibre-reinforced resin composite materials (which may have different thermal conductivities).

The load bearing structural part and the insulation part will typically be provided as separate, independent, or discrete parts which are connected/coupled together to form the wall plate. It is conceivable however that the wall plate could be provided as a unitary body e.g. of a material which can provide both a load bearing function and an insulating function Suitable materials can include polymeric materials.

The wall may comprise at least one aperture, in particular a window aperture (but conceivably a door aperture e.g. in a single storey building), and the wall plate may be configured to define a lintel for the at least one aperture. There may be a plurality of apertures (suitably at a common height in the wall e.g. having upper extents at a first height), and the wall plate may extend continuously along the upper edge surface of the wall so as to define lintels for each of the apertures.

The wall plate may have a height (which may be considered in a direction perpendicular to its main length direction, and suitably generally vertically in use of the wall plate) of up to around 400mm, optionally in a range of about 350mm to about 400mm. Generally speaking, apertures (particularly window apertures) in building walls have an upper extent or boundary which is between around 350mm to around 400mm below a top edge of the wall. In e.g. a masonry wall construction, a lintel is conventionally positioned on a course of bricks or blocks defining the upper extent of the window aperture, spanning across the aperture in a length direction of the wall. This provides a platform for further courses of bricks or blocks to be positioned above the aperture, which bring the wall up to a required final height.

Providing the wall plate which such a height may allow it to span a distance from the upper extent of any aperture in the load bearing structural wall to a full (or second) height of the structural wall.

The load-bearing structural wall may be or may form an inner wall in a cavity wall structure comprising the inner wall and an outer wall. The outer wall will not typically be a load-bearing structural wall, and may for example form a decorative and/or weatherproofing outer wall of the building. Reference to a wall being a load-bearing structural wall should be taken to mean that it supports structural loads of parts of the building, in particular the roof assembly. The outer wall may not be load-bearing in that it may not be required to support such structural loads (or at least any such structural loads may be primarily borne e.g. by the inner wall). Where the load-bearing structural wall comprises at least one aperture and defines a lintel, said apertures may be in the inner load-bearing structural wall, and so the lintel may be in said inner wall.

The load-bearing structural wall may have a structure selected from the group comprising masonry and a time-setting cementitious material. Masonry structure options include brick, block and combinations of the two. Material options can include clay based (particularly for bricks) and cementitious e.g. breeze or cinder blocks. Material options for time-setting cementitious material can include poured concrete and 3D printed concrete. In the case of poured concrete, this can encompass on-site manufacture (shuttering used to form the wall being assembled at a final location and concrete poured into the shuttering at that location), as well as off-site manufacture (e.g. concrete panels formed at an off-site location and shipped to the site for assembly to form the load-bearing structural wall). The upper edge surface of the wall may be defined by an upper surface or surfaces of masonry forming the wall (e.g. a top or uppermost row of bricks or blocks), or of cementitious material forming the wall.

Roof structural options can include pitched and flat. in the case of a pitched roof, this may comprise at least two roof portions which slope downwardly in opposite directions from an apex (or ridge) of the roof towards respective edge regions/eaves. Another pitched roof option comprises a single roof portion which extends from a high side at one edge of the building to a low side at an opposite edge. Flat roof options may not comprise a pitch, and so may be substantially flat/horizontal without a significant incline (although at least part of the roof e.g. an upper or outer surface, may be provided with a small incline, typically of less than 12.5°, to shed rainwater).

in the pitched roof option, the roof may comprise a plurality of roof trusses, each truss comprising a pair of rafters extending downwardly from the apex (two roof portions), or a single rafter sloping downwardly from the high side to the low side (single roof portion). The trusses may each be supported by or on the wall plate, typically both directly (e.g. in direct contact with the wall plate at a respective connection location), and indirectly (e.g. connected to one of the roof joists, which is in direct contact with the wall plate at a respective connection location). The trusses and/or the joists may define or comprise structural elements of the roof Other options for forming the roof (pitched or flat) include the use of panels, in particular structural insulated panels (SIPs). The panel(s) may be supported by or on the wall plate, optionally in direct contact with the top plate member of the wall plate (which may define the connection location), or in indirect contact with the top plate member (e.g. via a separate connecting or mounting component of the wall plate, positioned on the top plate member, and defining the connection location). Panels are generally planar, SIP panels in particular comprising an insulation layer sandwiched between inner and outer structural plates or sheets. A pitched roof typically has a pitch angle of between around 12.5° and 75°. A direct connection between a roof truss and a wall plate can be achieved by forming a notch or cutout in the rafter, to form a horizontal ledge which sits on the wall plate. This is not possible with panels, particularly SIP panels. In this situation, the wall plate may comprise an inclined surface defining an abutment for the panel. The inclined surface may be integral the top plate member of the wall plate, or a separate component of the wall plate may be connected to the top plate member and may define the inclined surface.

The wall may comprise a first wall portion which may extend to a first height, and a second wall portion, which may be defined by the wall plate, and which may extend to a second height which is greater than the first height. It will be understood that the second height is typically a maximum height of or defined by the wall, and which supports the roof above it. The building may be a single storey building, or a multiple storey building. The building may be a residential building, in particular a house (detached, semi-detached, terraced or bungalow), or an apartment block comprising a plurality of separate apartments.

According to a fourth aspect of the present invention, there is provided a method of forming a building roof, the method comprising the steps of connecting at least two elongate joists to an insulated wall plate at respective connection locations on the wall plate which are spaced apart along a main axis of the wall plate, to form a roof assembly which is a unitary structure comprising the elongate joists and the insulated wall plate, the insulated wall plate comprising a load-bearing structural part and an insulation part curried by the load-bearing structural part; connecting the roof assembly to a load-bearing structural wall of a building by seating the insulated wall plate on the load-bearing structural wall; and connecting one or more upper roof component to the roof assembly.

The insulated wall plate may be a first insulated wall plate, and the method may comprise connecting the elongate joists to a second insulated wall plate (which may form part of the roof assembly) at respective connection locations on the second wall plate which are spaced apart along its main axis. The second insulated wall plate may comprise a load-bearing structural part and an insulation part carried by the load-bearing structural part.

The step of connecting the roof assembly to the load-bearing structural wall may comprise seating the first insulated wall plate on a first load-bearing structural wall of the building, and may further comprise seating the second insulated wall plate on a second load-bearing structural wall of the building, to thereby connect the elongate joists to said second wall.

The elongate joists may each comprise a first end, and a second end opposite the first end, and the method may comprise connecting each of the elongate joists to the wall plate at their first ends. Where the roof assembly comprises first and second insulated wall plates, the method may comprise connecting each of the elongate joists to the first wall plate at their first ends, and to the second wall plate at their second ends.

The method may comprise connecting more than two elongate joists to the insulated wall plate, and may comprise connecting each joist to the wall plate at a respective connection location which is spaced apart along the main axis from the connection locations for other joists.

The method may comprise arranging the elongate joists so that they are substantially parallel to one another, in the unitary roof assembly structure. The method may comprise arranging the elongate joists so that that they are disposed transverse to the insulated wall plate, optionally to both of the first and second insulated wall plates (where present), and optionally substantially perpendicular to said plate(s).

The method may comprise configuring the unitary roof assembly structure so that it forms one or more of: a ceiling in the building; and a floor of a roof space or void of the building. The elongate joists may define floor and/or ceiling joists in the building.

The step of connecting the elongate joists to the wall plate may comprise positioning the wall plate in recesses of the joists, for example at their ends. A recess may be provided at each of the first and second ends of the joists, and the method may comprise positioning the first wall plate in the first joist recesses, and the second wall plate in the second joist recesses.

Connecting the joists to the wall plate may comprise positioning a support surface defined by the joists on an upper surface of the insulated wall plate.

The method may comprise forming at least one aperture (window and/or door) in the structural wall, and configuring the wall plate to define a lintel for the at least one aperture.

The method may comprise forming a plurality of apertures in the structural wall, suitably at a common height in the wall (e.g. having upper extents at a first height of the wall). The method may comprise arranging the wall plate so that it extends continuously along the upper edge surface of the first portion of the wall so as to define lintels for each of the apertures.

The method may comprise providing the wall plate with a height of at least around 350mm, optionally up to around 400mm, optionally in a range of about 350mm to about 400mm. Providing the wall plate with such a height may allow it to span a distance from the upper extent of any aperture in the load bearing structural wall to a final (e.g. second) height of the structural wall.

The method may comprise providing the building with a pitched roof or a flat roof. in the case of a pitched roof, the method may comprise providing at least two roof portions and arranging said portions so that they slope downwardly e.g. in opposite directions from an apex (or ridge) of the roof towards respective edge regions/eaves. in another pitched roof option, the method may comprise providing a single roof portion and arranging it so that it extends from a high side e.g. at one edge of the building to a low side e.g. at an opposite edge.

The step of connecting one or more upper roof component to the roof assembly may comprise connecting a plurality of roof trusses to the roof assembly (to one or both of the wall plate and at least one joist), each truss optionally comprising a pair of rafters extending downwardly from the apex (in a multiple roof portion option), or a single rafter sloping downwardly from the high side to the low side (in a single roof portion option). Where there are first and second wall plates, the method may comprise connecting each truss to one or both of the wall plates, and/or to a joist that is connected to both of the wall plates.

The flat roof may not comprise a pitch. The method may comprise providing a substantially flat/horizontal roof without a significant incline (although at least part of the roof e.g. an upper or outer surface, may be provided with a small incline to shed rainwater). The step of connecting one or more upper roof component to the roof assembly may comprise connecting a support panel for an outer weatherproofing layer to the roof assembly, optionally to the joists.

Other options for forming the roof (pitched or flat) include the use of panels, in particular structural insulated panels (SIPs). The step of connecting one or more upper roof component to the roof assembly may comprise arranging at least one such roof panel so that it is supported by or on the roof assembly, optionally the wall plate, and optionally in direct to contact with the top plate member of the wall plate (which may define the connection location), or in indirect contact with the top plate member (e.g. via a separate connecting or mounting component of the wall plate, positioned on the top plate member, and defining the connection location). Panels are generally planar. SIP panels in particular comprising an insulation layer sandwiched between inner and outer structural plates or sheets. In a panel based pitched roof, the method may comprise providing the wall plate with an inclined surface defining an abutment for the panel. The inclined surface may be provided by the top plate member of the wall plate, or by a separate component connected to the top plate member. Where there are first and second wall plates, the method may comprise: arranging at least one roof panel so that it is supported by both of the wall plates: or, for a pitched roof comprising an apex, arranging a first panel (or a first set of panels) so that it is supported by the first wall plate, and a second panel (or a second set of panels) so that it is supported by the second wall plate. The first and second panels (or first and second sets) may be disposed transverse to one another.

The method may be for constructing a single storey building, or a multiple storey building, and which may be a residential building, in particular a house (detached, semi-detached, terraced or bungalow), or an apartment block comprising a plurality of separate apartments.

Further features of the methods may be derived from the text set out elsewhere in this document, including in or with reference to any one or more of the first to third aspects of the invention.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of a building of a known type, comprising a cavity wall structure and a pitched roof supported on a load-bearing inner wall of the cavity wall structure; Fig. 2 is an enlarged cross-sectional side view of the building of Fig. 1, showing an cave region of the roof, and illustrating a situation in which insulation has been correctly fitted in the cave region; Fig. 3 is a view corresponding to Fig. 2, but illustrating a situation in which the insulation has not been correctly fitted in the cave region; Fig. 4 is a cross-sectional side view of a building which is similar to Fig. 2, but comprising a load-bearing inner wall, having an insulated wall plate, according to an embodiment of the invention, and again illustrating a situation in which insulation has not been correctly fitted in an cave region of the building roof; Fig. 5 is an enlarged perspective view of the wall plate shown in Fig. 4; Fig. 6 is a view of a wall plate according to another embodiment of the invention, which is similar to that of Fig. 5; Fig. 7 is a perspective view illustrating optional additional features of the wall plate of Fig. 4, and of a load-bearing structural wall carrying the wall plate; Fig. 8 is a view similar to Fig. 4 showing an cave region of an alternative building, comprising a flat roof, and a load-bearing inner wall having an insulated wall plate, according to an embodiment of the invention; Fig. 9 is a view similar to Fig. 4 showing an cave region of an alternative building comprising a pitched roof formed from structural insulated panels (SIPS), and having an alternative load-bearing wall having an insulated wall plate, according to an embodiment of the invention; Fig. 10 is a perspective view of a roof assembly forming part of a building construction system according to an embodiment of the invention, mid which comprises an insulated wall plate of the type shown in Fig. 5; and Fig. 11 is an enlarged side view of the roof assembly shown n Fig. 10, viewing in the direction of the arrow A. Turning firstly to Fig. 1, there is shown a perspective view of a building of a known type, in this case a residential building in the form of a detached house I0. The principles of the invention are not limited to a building of this type however, and can be applied to other buildings, in particular other residential buildings. This could include other house types such as semi-detached and terraced, as well as apartment blocks/condominiiims. The building could be multiple-storey ('story' in North America) as shown, or single storey, for example a bungalow.

The illustrated house 10 comprises a cavity wall structure and a pitched roof, best shown in the enlarged cross-sectional side view of Fig. 2, which illustrates an cave region 11 of the roof The cavity wall structure is indicated generally by reference numeral 12, and the pitched roof by reference numeral 14. The cavity wall structure 12 comprises a load-bearing inner wall 16, which forms an inner skin of the wall structure, and an outer wall 18 which forms an outer skin. The pitched roof 14 is supported on the load-bearing inner wall 16. The drawing illustrates a situation in which insulation 20 has been correctly fitted in the cave region I1, so that it extends fully into a void 22 located below an inner surface 24 of the roof 14 adjacent the cave, in the region of the inner and outer wall skins 16 and 18.

The insulation 20 has been fitted from within a main roof void 26, and passes over each of the inner and outer wall skins 16, 18, and in particular over an elongate timber wall plate 28 positioned on an upper edge surface 30 of the load-bearing inner wall 16. In a known fashion, the wall plate 28 supports the roof 14, in particular rafters 17 (one shown) which are seated on and connected to the wall plate. In the illustrated example, the wall plate 28 is positioned above a cavity closer 32, which is a thin flat plate (typically of a polymeric material) that closes off an insulated cavity 34 between the wall skins 16 and 18.

As will be understood from the discussion above, fitting of the insulation 20 in the cave void 22 can be problematic, due to the restricted access which is available from within the main roof void 26. This can result in the insulation being incorrectly fitted, as shown in Fig. 3, so that it does not extend fully into the void 22 over the wall plate 28, and the inner and outer wall skins 16, 18. This can be a particular problem when short timber struts 35 (often referred to as 'noggins') are positioned between adjacent ceiling joists 62, and which serve for stabilising ceiling boards 63 connected to the joists. Incorrect fitting of the insulation can result in thermal energy loss from within the building, in particular from a room 36 adjacent the incorrectly insulated eave region 11. In the exemplary building 10, the room 36 is located on an upper floor 38 (Fig. I). The room 36 is within a thennal envelope of the building and, in at least the winter months, will typically be heated, such as by a central heating system.

Thermal energy loss can occur through an inner wall layer 40 (e.g. plasterboard mounted on the inner load-bearing wall 16), into the fabric of the inner wall, and then into the incorrectly insulated void 22. This is indicated by the arrows 42 and 44 in Fig. 3, and can result in a cold zone forming towards an upper part 46 of the inner wall 16, with the consequences discussed above. in the illustrated example, the inner wall 16 is of a masonry construction, formed from rows (or courses) of breeze/cinder blocks (two shown and given the numerals 48 and 49). It will be understood that the timber material forming the wall plate 28 will typically have a lower thermal conductivity than the material of the breeze blocks 48, 49 and so will resist some thermal energy transfer, but that heat loss can still occur through the plate and indeed around it, in particular through the thin cavity closer 32.

The present invention will now be described, with reference to Fig. 4, which is a cross-sectional side view of a building which is similar to that shown in Fig. 2, and indicated by reference numeral 10a. Like components of the building 10a with the building 10 of Figs. 1 to 3 share the same reference numerals with the addition of the suffix 'a'. Only substantive differences will be described.

In the illustrated embodiment, a cavity wall structure 12a again comprises a load-bearing inner wall 16a and an outer wall I8a. A pitched roof I4a is supported on the inner wall 16a. The load-bearing inner wall 16a differs from the conventional structure shown in Figs. 1 to 3 in that it comprises a first portion, indicated generally by numeral 50, and a second portion 52 defined by an insulated wall plate 28a. The first wall portion 50 has a structure selected from the group comprising masonry and a time-setting cementitious material, and in the illustrated embodiment is masonry, formed from a series of courses of breeze/cinder blocks (one shown and given the numeral 48a).

The first wall portion 50 extends to a first height Hi taken e.g. from a foundation or footing of the building 10a on which the wall 16a sits (the foundation indicated schematically by numeral 51), and comprises an upper edge surface 54. The first wall portion 50 forms a majority of the wall 16a. The insulated wall plate 28a defining the second wall portion 52 is positioned on the upper edge surface 54, typically on a bed of cementitious mortar.

As best shown in the enlarged perspective view of Fig. 5, the insulated wall plate 28a comprises a load-bearing structural part 56 and an insulation part 58 carried by the load-bearing structural part. The second wall portion 52 extends the wall to a second height H2 above the foundation 5I. which is greater than the first height HI, at which it defines connection locations 60 for structural elements of the roof. The structural elements could be rafters (e.g. a rafter 17a forming part of a truss of the pitched roof 14a), ceiling joists (e.g. joist 62a shown in the drawing), or some other components of the roof.

The insulated wall plate 28a helps to address problems which occur in conventional building construction, in which inadequately insulated roof space voids lead to heat loss and cold spots forming on an upper part of a structural wall. This is because the insulated wall plate 28a effectively provides the upper (or second) portion 52 of the inner load-bearing wall 16a. Even if insulation is subsequently positioned in a sub-optimal fashion (e.g. as shown in Fig. 4, in which it does not extend filly into a void 22a adjacent an cave region 11a of the pitched roof 14a), the insulation part 58 of the wall plate 28a serves to resist thermal energy transfer through the wall structure near the void, and so the formation of cold spots.

Further features of the wall plate 28a, as well as the load-bearing structural wall 16a and the building I Oa, will now be described in the embodiment shown in Fig. 5, the insulation part 58 of the wall plate 28a is connected to the load-bearing structural part 56. The insulation part 58 is provided as an elongate strip of a substantially rigid insulation material, and engages the structural part 26 in an interference fit (which retains the insulation part in connection with the structural part). For example, the insulation part 58 may be slightly oversized relative to a cavity 64 defined by the structural part 56 and which is shaped to receive the insulation part, so that the insulation part is compressed during fitting to the structural part. In a variation however (or indeed as an additional option), the insulation part 58 may be bonded to the structural part 56. Bonding may be achieved using an adhesive, or the insulation material itself may have inherent adhesive properties.

For example, a manufacturing process for the wall plate 28a may involve applying insulation material to the structural part 56 in a fluid or flowable state (e.g. as a spray foam), the to insulation material setting over time to a substantially solid state in which it is no longer fluid or flowable, and in which it defines the insulation part. During setting, a volume of the insulation part 58 may increase slightly to provide an interference fit, and/or the material may provide an adhesive bond to the structural part.

It will be understood however that friction between the insulation part 58 and the structural part 56 within the cavity 64 may be sufficient to retain the insulation part in the cavity without specifically forming an interference fit, or requiring bonding.

The thermal conductivity of a material forming the insulation part 28 may be lower than a thermal conductivity of a material forming the load-bearing structural part 56. The insulation part 58 may be of a material having a thermal conductivity of up to around 0.04W/m.K, and suitably in a range of about 0.022 to about 0.04W/m.K, in particular about 0.035 to about 0.04Whn.K. Suitable insulation materials can include polymers such as extruded polystyrene (XPS) and expanded polystyrene (EPS), which have thermal conductivities that are typically in the range of about 0.035 to about 0.04W/m.K. Flowable insulation materials such as foams as described above may be of a polymeric material such as polyurethane (PU), which can have a lower thermal conductivity, e.g. in the range of about 0.022 to about 0.028W/m.K.

The load-bearing structural part 56 of the wall plate 28a is elongate and comprise the cavity 64 as described above, which takes the form of a channel, groove. recess or the like shaped to receive the insulation part 58. The load bearing structural part 56 comprises a top plate member 66 which defines an upper edge surface 68 of the wall plate 28a. The top plate member 66 also defines the connection locations 60. The load bearing structural part 56 also comprises a bottom plate member 70 which defines a bottom edge surface 72 of the wall plate 28a, which is configured to rest on the upper edge surface 54 of the first wall portion 50.

The top and bottom plate members 66 and 70 each extend in a main length direction of the structural part 56, and one or more connecting member extends between and connects the top and bottom plate members. In the illustrated embodiment, the load-bearing structural part 56 is substantially hollow, comprising the interior cavity 64, and takes the general form of an elongate hollow box (suitably generally rectangular in shape in cross-section as shown). The cavity 64 is open at one or both of first and second ends of the hollow box forming the structural part, the first end shown in the drawing and indicated by numeral 74.

The load-bearing structural part 64 of this embodiment comprises a pair of connecting members 76 and 78, each of which extends between and connects the top and bottom plate members 66, 70. The connecting members 76, 78 are arranged so that the cavity 64 is bound by a lower surface 80 of the top plate member 66, internal surfaces 82 and 84 of the connecting members 76 and 78, and an upper surface 86 of the bottom plate member 70. The connecting members 76, 78 each take the general form of a flat elongate panel, member 76 forming a first panel and member 78 a second panel. The first panel 76 is coupled to and extends between respective first side surfaces of the top and bottom plate members 66/70.

and the second panel 78 is coupled to and extends between respective second side surfaces of the top and bottom plate members.

A thermal conductivity of a material forming the load bearing structural part 56 of the wall plate 28a is higher than a thermal conductivity of a material forming the insulating part 58.

The load bearing structural part 56 may be of a material having a thermal conductivity of up to around 0.17W/m.K, and suitably in a range of about 0.11 to about 0.17W/m.K. Suitable materials can include timber (softwoods and hardwoods), and timber based composite materials including wood fibreboard and chipboard, and laminates such as plywood. Other materials can include polymeric materials, and composite materials such as fibre-reinforced resin composite materials (which may have different thermal conductivities).

The wall plate 28a is typically constructed by connecting the first side panel 76 to the top and bottom plate members 66 and 70 to form the cavity 64, which at this time is open to a second side of the wall plate. The strip of insulation forming the insulation part 58 is preformed or precut to the correct size (optionally slightly oversized to provide an interference fit), and fitted into the cavity 64. The second side panel 78 is then connected to the top and bottom plate members 66 and 70 to close the cavity 64 and secure the insulation part 58 within the cavity.

The panels 76 and 78 can be connected to the plate members 66 and 70 using any suitable method, including mechanical fixings such as screws or nails, and/or by bonding e.g. using an adhesive. This provides a relatively rigid structure in which structural loads imparted on the wall plate 28a by the roof 14a during use are applied to the top plate member 66, and transmitted through the side panels 76 and 78 to the bottom plate member 70, and hence to the first wall portion 50 on which the wall plate sits.

The wall plate 28a itself is typically seated on a bed of cementitious mortar on the upper edge surface 54 of the first wall portion 50, and secured using generally L-shaped straps or ties (not shown) of a conventional type, which pass over the upper edge surface 68 of the top plate member 66, down an outer surface 88 of the second side panel 78, and over an inside surface 90 (Fig. 4) of the first wall portion 50.

A wall plate in accordance with another embodiment of the invention is shown in Fig. 6, which is a perspective view similar to Fig. 5. The wall plate is indicated generally by reference numeral 28b, and may provide the second wall portion of the load-bearing structural wall 16a shown in Fig. 4 (or indeed of any of the other structural walls described elsewhere in this document). Like components of the wall plate 28b with the wall plate 28a share the same reference numerals, with the addition of the suffix 'b'. Only substantive differences will be described.

In the wall plate 28b of this embodiment, a load-bearing structural part 56b of the wall plate comprises a single connecting member 76b, which forms a structural core of the structural part. The structural part 56b again comprises top and bottom plate members 66b and 70b.

The plate members 66b, 70b and the structural core 76b are provided as separate components which are coupled together, but in a variation could be provided as a single or unitary component. As can be seen from the drawing, a width of the structural core 76b (considered in a direction perpendicular to the main length direction of the wall plate, and suitably generally horizontally in use) is less than a width of both of the top and bottom plate members 66b, 70b. The structural core 76b is disposed generally along a centreline of the structural part 56b, and connected with the top and bottom plate members generally at midpoints of the plate members, considered in a width direction.

As with the wall plate 28b, the structural part 56b is typically of timber or a timber-based material. A particularly suitable option for the structural core 76b is a plywood material, which has good strength characteristics. As can be seen from the drawing, the structural core 76b may be considered to form a rib which extends between and connects the top and bottom plate members 66b, 70b.

In this embodiment, first and second channels 64b and 64b' are disposed on both of the lateral sides of the structural core 76b, and receive respective insulation parts 58b and 58b' of the wall plate 28b. The channels 64b and 64b' are each bound by a lower surface 80b of the top plate member 66b, a side surface 92/94 of the structural core 76b, and an upper surface 86b of the bottom plate member 70b. The channels 64b and 64b' are each open on one side, suitably on a side facing laterally and/or away from the structural core 76b. As can be seen, the result of this is that the load bearing structural part 56b is generally I-shaped in cross-section.

The wall plate 28b of this embodiment may provide a good balance of structural strength with ease of installation of insulation material in the channels 64b and 64b'. In particular, it may be possible to fully construct the load-bearing structural part 56b prior to installing the insulation material in the channels 64b and 64W, following any of the methods discussed above. A particularly preferred option may however be strips of substantially rigid insulation material installed in an interference fit and/or by bonding.

Returning to the wall plate 28a, and referring now to Fig. 7, there is shown a perspective view illustrating optional additional features of the wall plate and of the load-bearing structural wall I 6a carrying the wall plate.

As can be seen from the drawing, the structural wall 16a comprises a plurality of apertures, in this case window apertures 96 and 98 which extend through the wall from a front to a back surface. It will be understood that, in the cavity wall structure 12a of the building 10a, a corresponding aperture (not shown) is provided in the outer wall skin 18a, and that these are aligned and together provide for the positioning of window frames of windows (not shown) within the wall structure. Of course, other apertures could be provided, for example a door aperture (particularly in a single storey building such as a bungalow).

The wall plate 28a is configured to define a lintel for the window apertures 96 and 98, as shown in the drawing. The window apertures 96 and 98 extend to a common height in the wall 16a, and have upper extents which are at the first height H1 discussed above. As can be seen, the wall plate 28a extends continuously along the upper edge surface 54 of the first portion 50 of the wall 16a, so as to define lintels for each of the apertures 96, 98.

To facilitate this, the wall plate 28a has a height D (considered in a direction perpendicular to its main length direction, suitably generally vertically in use of the wall plate) of up to around 400mm, and particularly in a range of about 350mm to about 400mm. Generally speaking, window apertures in building walls have an upper extent or boundary which is between around 350mm to around 400mm below a top cdgc of a wall. In a masonry wall construction of the type shown, a lintel is conventionally positioned on a course of bricks or blocks defining the upper extent of the window aperture, spanning across the aperture in a length direction of the wall. This provides a platform for further courses of bricks or blocks to be positioned above the aperture, which bring the wall up to a required final height. Providing the wall plate 28a which such a height D allows it to span a distance from the upper extent of the window apertures 96, 98 to the second height H2 of the structural wall 16a. This effectively supports the portion of the roof 14a structure located above the window apertures 96/98, so that the roof loading is not borne by window frames located in the apertures.

Masonry structure options for the load-bearing structural wall I6adiscussed above include brick, block and combinations of the two. Material options can include clay based (particularly for bricks) and cementitious e.g. breeze or cinder blocks. Other options for forming the cavity wall structure 12a include the use of a time-setting cementitious material, for example poured concrete and 3D printed concrete. in the case of poured concrete, this can encompass on-site manufacture (shuttering used to fonmn the wall being assembled at a final location and concrete poured into the shuttering at that location), as well as off-site manufacture (e.g. concrete panels formed at an off-site location and shipped to the site for assembly to form the load-bearing structural wall 16a). In these cases, the upper edge surface 54 of the first portion 50 of the wall 16a would be defined by the cementitious material forming said wall portion.

The first wall portion 50 forms a majority of the wall I 6a, and so at least 50% of a total height of the wall. The first wall portion 50 may however form more than 50% of the total wall height, optionally up to around perhaps 85-95%. Typical heights of load-bearing (external) walls of residential buildings vary from between around 2.4m to around 3m, per storey, in the UK and other countries. For a single storey residential building (such as a bungalow), the first wall portion 50 may form between around 85% to around 90% of the to total wall height. For a two-storey building (such as a house), the first wall portion 50 may form between around 93% to around 95% of the total wall height. These values take account of the typical 350-400mm height D of the wall plate 28a forming the second wall portion 52.

Roof structural options can include pitched and flat. in the case of a pitched roof, this can comprise at least two roof portions which slope downwardly in opposite directions from an apex (or ridge) of the roof towards respective edge regions/eaves. Another pitched roof option comprises a single roof portion which extends from a high side at one edge of the building to a low side at an opposite edge.

Flat roof options may not comprise a pitch, and so may be substantially flat/horizontal without a significant incline (although at least part of the roof c.g. an upper or outer surface, may be provided with a small incline, typically of less than 12.5°, to shed rainwater). This is illustrated in Fig. 8, which is a view similar to Fig. 4 showing an cave region of an alternative building 10c comprising a flat roof, and a load-bearing inner wall 16e having an insulated wall plate 28c (which has the same structure as the wall plate 28b described above). Like components of the building 10e with the building 10a share the same reference numerals, with the suffix 'a' replaced by the suffix 'c'.

As can be seen, the roof 14c comprises roof joists (one shown and given the numeral I00) supported by the load bearing wall 16e, which forms part of a cavity wall 12c of the type described above. As is well-known, ventilation spaces (not shown) are defined between adjacent joists, and a layer of rigid insulation 102 is spans across the top of the joists 100. An outer weatherproof layer 104 provides a water-tight bather, and may be provided with a small incline (of the order of a few degrees) to naturally shed rainwater from the roof 14c. A void 22c at the cave region can be filled with insulation material 106 during construction, which is typically easier to install than insulation in the void of a pitched roof as described above. Nonetheless, an additional thermal barrier can be provided through the use of the insulated wall plate 28c of the invention, and/or the wall plate can provide a barrier in the event of incorrectly installed insulation in the void 22c.

Turning now to Fig. 9, there is shown a view similar to Fig. 4 showing an cave region of an alternative building 10d comprising a pitched roof formed from structural insulated panels (SIPs), and having an alternative load-bearing wall having an insulated wall plate, according to another embodiment of the invention. Like components of the building 10d with the building 10a share the same reference numerals, with the suffix 'a' replaced by the suffix 'd'.

In this embodiment, the building 10d comprises a single skin wall structure 12d having a load-bearing wall 16d, typically referred to as a 'solid wall' in the construction industry.

Single skin wall options include any of those discussed herein, but particularly a poured concrete wall structure, and a wall structure formed e.g. from cement-based blocks. The latter option is shown in the drawing, with breeze blocks forming a first portion 50d of the wall. An external insulation layer 108 is secured to the wall 16d, and a weatherproofing layer 110 is provided outermost. As in Fig. 8, an insulated wall plate 28d (again having the same structure as the wall plate 28b described above) is fitted to an upper edge surface 54d of the first portion 50d of the wall 16d.

As mentioned above, the building 10d comprises a pitched roof I 4d, which in this case is formed from SIPs. One such SIP can be seen in the drawing, and is indicated by numeral 112. As is well known, the SIP 112 comprises a core or layer 114 of an insulating material, which is sandwiched between structural facing panels 116 and 118 (typically timber based e.g. plywood). The SIP 112 is supported by or on the insulated wall plate 28d, in this case via a mounting component 120 positioned on a top plate member 66d of the wall plate which defines a connection location 60d. As can be seen, the mounting component 120 has an inclined face 122 which abuts the SIP 112, and is typically of a timber or timber-based material. The mounting component is connected to the top plate member 66d of the wall plate 28d, suitably via a mechanical fixing and/or using an adhesive. Insulation 20d is installed between adjacent ceiling joists (not shown) that are supported on the wall plate 28b, to provide a well-insulated roof structure.

In a variation, the top plate member 66d of the wall plate 28d may comprise or provide an integral inclined abutment face 122 for the SIP 112, for example by appropriate shaping of the upper edge surface of the top plate member. This provides for a direct mounting of the SIP 112 on the top plate member 66d (i.e, in direct contact with the top plate member at the connection location 60d).

Turning now to Fig. 10, there is shown a perspective view of a roof assembly forming part of a building construction system according to an embodiment of the invention, and which comprises an insulated wall plate of the type described above. The roof assembly is indicated generally by reference numeral 124, and is configured to be connected to a load-bearing structural wall to form a building construction system comprising the wall and the roof assembly, and of course a constructed building comprising the roof assembly. The load-bearing structural wall can be the wall 16a of the building I Oa shown in Fig. 4. The wall plate is indicated by numeral 28e. Like components of the wall plate 28e with the wall plate 28a share the same reference numerals, with the suffix 'a' replaced by the suffix 1e1.

The roof assembly 124 comprises at least two elongate joists 126 and 128, and the insulated wall plate 28e. The wall plate 28e has the same structure as the wall plate 28a shown in Fig. 5, and therefore comprises a load-bearing structural part 56e and an insulation part 58e carried by the load-bearing structural part. This is best shown in the enlarged side view of Fig. 11, viewing in the direction of the arrow A in Fig. 10. It will be understood however that the roof assembly 124 may comprise an insulated wall plate of an alternative structure, such as the wall plate 28b shown in Fig. 6.

The wall plate 28c has a main axis 130 extending along a length direction of the plate. As best shown in Fig. 10, the joists 126 and 128 are each connected to the wall plate at respective connection locations 132 and 134 on the wall plate 28e which are spaced apart along its main axis 130, to fonn a unitary structure defining the roof assembly and comprising the elongate joists and the wall plate. As with the wall plate 28a described above, the wall plate 28e is configured to be seated on the load-bearing structural wall I 6a, to thereby connect the elongate joists to the wall. In particular, the wall plate 28e can be seated on the upper edge surface 54 of the first portion 50 of the load-bearing structural wall 16a.

The roof assembly 124 typically comprises more than two joists, and in the illustrated embodiment comprises seven joists, the joists 126 and 128 forming end joists of the assembly, and five fiwther joists 136 to 144 provided between the end joists. The further joists 136 to 144 are connected to the wall plate 28e at respective connection locations 146 to 154.

The roof assembly 124 also typically comprises more than one insulated wall plate. In the illustrated embodiment, the roof assembly 124 comprises the insulated wall plate 28e (which forms a first insulated wall plate of the assembly), and a second insulated wall plate 28e' of like construction to the wall plate 28e. Like components of the second wall plate 28e' with the first wall plate 28c share the same reference numerals with the addition of the suffix '. Of course, the wall plate 28e' may again take an alternative form, such as that of the wall plate 28b.

The second insulated wall plate 28e' thus comprises a load-bearing structural part 56e', an insulation part 58e' carried by the load-bearing structural part, and amain axis 130' extending along a length direction of the wall plate. The elongate joists 126, 128 and 136 to 144 are each connected to the second wall plate 28e' at respective connection locations 132', 134' and 146' to 154' on the second wall plate which are spaced apart along its main axis 130'.

The load-bearing structural wall 16a on which the first insulated wall plate 28e is seated forms a first such wall of the building 10a. The second insulated wall plate 28e' is configured to be seated on a second load-bearing structural wall I6a' of the building, to thereby connect the elongate joists to said second wall. The walls 16a and 16a' are shown in broken outline in Fig. II. As can be seen, the first and second insulated wall plates 28e and 28e' are disposed substantially parallel to each other in the unitary roof assembly structure, and arc spaced apart in length directions of the various elongate joists.

The elongate joists 126, 128 and 136-144 each comprise a first end, and a second end opposite the first end. Referring just to the first elongate joist 126 shown in Fig. 11, the joist comprises a first end 156 and a second end 158. The first and second ends of all of the joists will be referred to using these numerals. The elongate joists arc each connected to the first wall plate 280 at their first ends 156, and to the second wall plate 28c' at their second ends 158. The elongate joists themselves are arranged so that they are substantially parallel to one another in the unitary roof assembly 124 structure, and are disposed transverse to the first and second insulated wall plates 28e and 28e', suitably substantially perpendicular as shown in Fig. 10.

As can be seen, the unitary roof assembly 124 structure takes the general form of a frame or frame-type assembly comprising the various joists 126, 128 and 136-144, and the first and second insulated wall plates 28e and 28e'. The roof assembly 124 can be constructed away from its final location (on the load-bearing walls 16a and 16a'), for example on a building site, or potentially at a remote location and then transported to the site e.g. by a road vehicle.

This can provide numerous advantages, including time and cost savings. This is because conventional construction methods require that wall plates be separately connected to respective load-bearing walls, and joists subsequently individually positioned on and connected to the wall plates. The roof assembly 124 in contrast can be constructed as a single (or unitary) structure, e.g. at ground level next to the building 10a location, and then raised up to the required position (e.g. using a crane) and connected to the walls 16a, 16a'.

Once in position, the unitary roof assembly 124 effectively forms a ceiling in the building 10a (for example for a room 36a of the building -Fig.4), as well as a floor of a roof space 26a.

The various joists 126, 128 and 136-144 are therefore configured to define floor and ceiling joists in the building 10a The joists each comprise a recess shaped to receive the insulated wall plate, suitably at their ends. Referring again to the joist 126 in Fig. 11, the joist comprises a recess 160 at its first end 156, and a recess 162 at its second end 158, for respectively receiving the first and second wall plates 28e and 28c'. The elongate joists each comprise support surfaces configured to rest on upper surfaces of the wall plates 28e and 28e', for supporting the joists on the wall plates. Referring just to the end 156 of the joist 126, a support surface 164 is configured to rest on an upper surface 68e of the first wall plate 28e. The joist 126 is connected to the wall plates 28e and 28e' via a mechanical fixing (not shown, e.g. one or more bolt, screw, nail and/or a dedicated fixing plate), but can additionally or alternatively be bonded to the wall plates (e.g. using an adhesive).

The elongate joists can take any suitable form, but in the illustrated embodiment take the form of composite joists comprising elongate upper 166 and lower 168 support members, and a connecting member 170 extending between and connecting the upper and lower support members. All of the remaining joists 128 and 136-144 have a similar structure, but only that of the joist 126 is shown in the drawings.

The support surface 164 is defined on or by a part of the joist 126 which extends from a main portion of the joist, specifically by ends of the upper support member 166. In the composite joists, the upper and lower support members 166 and 168 are of a first material, and the connecting member 170 is of a second material which is different to the first material.

Material properties of the first and second materials may differ, e.g. the first material will typically be a timber or timber-based material, and the second material a metal or metal alloy material.

The joist 126 has a non-solid cross-section, considered in a vertical plane/height direction.

The connection member 170 takes the general form of a web, comprising web members 172 which extend in directions transverse to a main longitudinal axis 174 of the joist, between the upper and lower support members 166 and 168, to connect the support members. The web 170 has a generally undulating profile, considered in the direction of the main axis 174. The web members 172 take the form of struts, and the web 170 comprises integral connection plates 176 and 178 which extend over side surfaces of the upper and lower support members 166 and 168. These serve for securing the struts 172 to the support members 166, 168 e.g. via integral connectors such as protrusions on the plates, and/or separate connectors such as screws, pins or nails which pass through the plates. Composite joists of this type are commercially available from numerous suppliers, including from MiTek® UK and Ireland under the POST-JOISTTm brand. The use of open-structure joists of this type is beneficial, as they provide openings through which e.g. service conduits can pass. In an alternative however, the elongate joists can have a substantially solid cross-section, and may be of a single material (e.g. a timber or timber-based material).

Following connection of the roof assembly 124 to the walls 16a and 16a', upper roof components are connected to the roof assembly to complete the building roof This could include roof trusses, and so for example rafters 17a of the roof truss shown in Fig. 4. Of course, in a pitched roof comprising roof trusses each having a pair of rafters extending downwardly from an apex, each truss will typically be connected to both of the wall plates 28e and 28e', and/or to one of the joists 126, 128 and 136-144 that are connected to the wall plates. For example, first and second truss rafters extending from the roof apex may be connected respectively to the first wall plate 28e and the second wall plate 28e', and/or to respective first and second ends 156 and 158 of the joists.

In the case of a flat roof, an upper roof component may be connected to the roof assembly 124 (suitably to the joists), for example a support panel (not shown) for an outer weatherproofing layer to the joists. Referring again to Fig. 8, the rigid insulation 102 may sit on a panel (not shown) above the joists, or could be seated directly on the joists.

Where the roof comprises panels (in particular SIPs as in Fig. 9), upper roof components in the form of the SIPs 112 may be connected to the roof assembly 124, and so for example to the wall plate 28e. it will be understood that, for a pitched roof comprising an apex, a first panel (or a first set of panels) may be supported by the first wall plate 28c, and a second panel (or a second set of panels) by the second wall plate 28e'. The first and second panels will, in this scenario, be disposed transverse to one another. Of course, the roof (or each portion of a pitched roof comprising such an apex) may be made up of a plurality of such panels, in which case more than one panel may be supported from the or each wall plate 28e/28e'.

Various modifications may be made to the foregoing without departing from the spirit or scope of the present invention.

For example, the wall plate could be provided as a unitary body e.g. of a material which can provide both a load bearing function and an insulating function. Suitable materials can include polymeric materials.

Further aspects and/or embodiments of the invention may combine the features of one or more aspect and/or embodiment disclosed in this document. Accordingly, such further aspects and/or embodiments may comprise one or more feature selected from one or more aspect or embodiment of the invention disclosed in this document. in particular, any of the insulated wall plates disclosed in this document may form part of any one of the load-bearing wall structures disclosed in this document. Any of the load-bearing wall structures disclosed in this document and may form part of a building having any one of the roof structures disclosed in this document.

Unless explicitly implied by context or stated in the document, the features of any method or process disclosed in this document need not necessarily be performed in the precise order set out in the relevant text and/or drawings Accordingly, any method or process disclosed in this document may be capable of being performed in an order other than that specifically set out in the relevant text/drawings, if circumstances permit.

Features disclosed in this document (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Accordingly, features disclosed in this document may represent only one example of a generic series of equivalent or similar features.

Claims

CLAIMS1. A roof assembly for a building, the roof assembly comprising: at least two elongate joists; and an insulated wall plate comprising a load-bearing structural part, an insulation part carried by the load-bearing structural part, and a main axis extending along a length direction of the wall plate; in which the elongate joists are connected to the wall plate at respective connection locations on the wall plate which are spaced apart along its main axis; in which the roof assembly is configured to be installed in the building as a unitary structure comprising the elongate joists and the insulated wall plate; and in which the insulated wall plate is configured to be seated on a load-bearing structural wall of the building, to thereby connect the elongate joists to the wall.
2. A roof assembly as claimed in claim 1, in which: the insulated wall plate is a first insulated wall plate, and the roof assembly comprises a second insulated wall plate, the second insulated wall plate comprising a load-bearing structural part, an insulation part carried by the load-bearing structural part, and a main axis extending along a length direction of the wall plate: and the elongate joists are connected to the second wall plate at respective connection locations on the second wall plate which are spaced apart along its main axis.
3. A roof assembly as claimed in claim 2, in which the first insulated wall plate is configured to be seated on a first load-bearing structural wall of the building, and the second insulated wall plate is configured to be seated on a second load-bearing structural wall of the building, to thereby connect the elongate joists to said second wall.
A roof assembly as claimed in either of claims 2 or 3, in which: the elongate joists each comprise a first end, and a second end opposite the first end; and the elongate joists are each connected to the first wall plate at their first ends, and to the second wall plate at their second ends.
5. A roof assembly as claimed in claim 1, comprising more than two elongate joists, each joist being connected to the insulated wall plate at a respective connection location which is spaced apart along the main axis from the connection locations for other joists.
6. A roof assembly as claimed in any one of claims 2 to 4, comprising more than two elongate joists, each joist having a first end and a second end opposite the first end, and being connected to the first wall plate at their first ends, and to the second wall plate at their second ends.
7. A roof assembly as claimed in any preceding claim, in which the elongate joists each comprise a recess shaped to receive the insulated wall plate.
8. A roof assembly as claimed in any one of claims 2 to 4, in which the elongate joists each comprise recess at their first and second ends, for respectively receiving the first and second wall plates.
9. A roof assembly as claimed in either of claims 7 or 8, in which the elongate joists each comprise a support surface configured to rest on an upper surface of the insulated wall plate, for supporting the joists on the wall plate, the support surfaces defined by parts of the 20 joists which extend from a main portion of the joist.
10. A roof assembly as claimed in any preceding claim, in which the elongate joists each comprise elongate upper and lower support members and at least one connection member extending between and connecting the upper and lower support members.
11. A roof assembly as claimed in any preceding claim, in which the insulation part of the wall plate comprises at least one elongate strip of insulation material which is connected to the structural part of the wall plate.
12. A roof assembly as claimed in as claimed in claim 11, in which: the insulation part of the wall plate is connected to the structural part of the wall plate in an interference fit; and/or the insulation part of the wall plate is bonded to the structural part of the wall plate.
13. A roof assembly as claimed in as claimed in any preceding claim, in which a thermal conductivity of a material forming the insulation part of the wall plate is lower than a thermal conductivity of a material forming the load-bearing stiuctural part, the insulation part material having a thermal conductivity of up to around 0.04W/m.K
14. A roof assembly as claimed in as claimed in any preceding claim, in which the load-bearing structural part of the wall plate is elongate and comprises at least one channel which is shaped to receive the insulation part.
15. A roof assembly as claimed in as claimed in claim 14, in which the load bearing structural part of the wall plate comprises: a top plate member defining an upper edge surface of the wall plate which provides the connection locations: a bottom plate member defining a bottom edge surface of the wall plate which is configured to rest on the upper edge surface of the wall; and at least one connecting member which extends between and connects the top and bottom plate members.
16. A roof assembly as claimed in as claimed in claim 15, in which the load-bearing structural part of the wall plate is substantially hollow, comprising an internal cavity which defines the channel.
17. A roof assembly as claimed in claim 16, in which the load bearing structural part of the wall plate takes the general form of an elongate hollow box defining said internal cavity.and further comprises a pair of connecting members which each extend between and connect the top and bottom plate members.
18. A roof assembly as claimed in as claimed in claim 15, in which the load-bearing structural part of the wall plate comprises a single connecting member which forms a structural core of said part, a width of the structural core being less than a width of the top and bottom plate members, and the structural core being disposed generally along a centreline of the load-bearing structural part and connecting with the top and bottom plate members generally at a midpoint of the members.
19. A roof assembly as claimed in as claimed in claim 18, in which said channel of the load-bearing structural part of the wall plate is disposed on a side of the structural core and open on a side facing laterally, away from the structural core.
20. A roof assembly as claimed in claim 19, in which the load-bearing structural part of the wall plate comprises a first channel which is disposed on a first side of the structural core, and a second channel which is disposed on a second side of the structural core.
21. A roof assembly as claimed in any preceding claim, in which a thermal conductivity of a material forming the load bearing structural part of the wall plate is higher than a thermal conductivity of a material forming the insulating part, the load bearing structural part material having a thermal conductivity of up to around 0.17V^Um.K
22. A roof assembly as claimed in as claimed in any preceding claim, in which the wall 15 plate has a height of up to around 400mm, optionally in a range of about 350mm to about 400mm.
23. A building construction system comprising: a load-bearing structural wall; and a roof assembly configured to be connected to the load-bearing structural wall, the roof assembly comprising: at least two elongate joists; and an insulated wall plate comprising a load-bearing structural part, an insulation part carried by the load-bearing structural part, and amain axis extending along a length direction of the wall plate; in which the elongate joists are connected to the wall plate at respective connection locations on the wall plate which are spaced apart along its main axis, to form a unitary structure defining the roof assembly and comprising the elongate joists and the wall plate; and in which the insulated wall plate is configured to be seated on the load-bearing structural wall, to thereby connect the elongate joists to the wall.
24. A building comprising a load-bearing structural wall, and a roof assembly connected to the load-bearing structural wall, in which the roof assembly is a unitary structure comprising: at least two elongate joists; and an insulated wall plate comprising a load-bearing structural part, an insulation part carried by the load-bearing structural part, and a main axis extending along a length direction of the wall plate, the elongate joists being connected to the wall plate at respective connection locations on the wall plate which are spaced apart along its main axis; in which the insulated wall plate is seated on the load-bearing structural wall, to thereby connect the elongate joists to the wall; and in which the roof assembly is configured to be installed in the building as a unitary structure comprising the elongate joists and the insulated wall plate.
25. A building as claimed in claim 24, comprising the roof assembly according to any one of claims 2 to 22.
26. A method of forming a building roof, the method comprising the steps of: connecting at least two elongate joists to an insulated wall plate at respective connection locations on the wall plate which are spaced apart along a main axis of the wall plate, to form a roof assembly which is a unitary structure comprising the elongate joists and the insulated wall plate, the insulated wall plate comprising a load-bearing structural part and an insulation part carried by the load-bearing structural part: connecting the roof assembly to a load-bearing structural wall of a building by seating the insulated wall plate on the load-bearing structural wall; and connecting one or more upper roof component to the roof assembly.
27. A method as claimed in claim 26, in which the insulated wall plate is a first insulated wall plate, and the method comprises connecting the elongate joists to a second insulated wall plate of the roof assembly at respective connection locations on the second wall plate which arc spaced apart along its main axis, the second insulated wall plate comprising a load-bearing structural part and an insulation part carried by the load-bearing structural part.
28. A method as claimed in claim 27, in which the step of connecting the roof assembly to the load-bearing structural wall comprises seating the first insulated wall plate on a first load-bearing structural wall of the building, and seating the second insulated wall plate on a second load-bearing structural wall of the building, to thereby, connect the elongate joists to said second wall.
29. A method as claimed in either of claims 27 or 28, in which the elongate joists each comprise a first end, and a second end opposite the first end, and the method comprises connecting each of the elongate joists to the first wall plate at their first ends, and to the second wall plate at their second ends.
30. A method as claimed in any one of claims 26 to 29, in which the step of connecting the elongate joists to the wall plate comprises positioning the wall plate in recesses of the joists.
31. A method as claimed in any one of claims 27 to 29, comprising positioning the first wall plate in first recesses of the joists, and positioning the second wall plate in second recesses of the joists, and in which the step of connecting the joists to the wall plate comprises positioning support surfaces defined by the joists on upper surface of the insulated wall plates.
32. A method as claimed in any one of claims 26 to 31,, comprising providing the wall plate with a height in a range of about 350mm to about 400mm.
33. A method as claimed in any one of claims 26 to 32, in which the step of connecting one or more upper roof component to the roof assembly comprises arranging at least one roof panel so that it is supported by the wall plate.
34. A method as claimed in claim 33, comprising arranging said roof panel so that it is: in direct contact with a top plate member of the wall plate, which defines the connection location; or in indirect contact with a top plate member of the wall plate, via a separate connecting component positioned on the top plate member, the connecting component defining the connection location.
35. A method as claimed in claim 34, in which the at least one panel is a structural insulated panel (SIP), the roof is a pitched roof, and the method comprises providing the wall plate with an inclined surface defining an abutment for the SIP, the inclined surface being provided: by the top plate member of the wall plate; or by the separate connecting component which is connected to the top plate member.
36. A method as claimed in any one of claims 33 to 35, in which the method is a method of forming a pitched building roof comprising an apex, and the method comprises: arranging a first set of panels so that they are supported by the first wall plate; and arranging a second set of panels so that they are supported by the second wall plate, the panels in the first set being disposed transverse to the panels in the second set.